scholarly journals Differential effects of glucagon-like peptide-1 on microvascular recruitment and glucose metabolism in short- and long-term insulin resistance

2015 ◽  
Vol 593 (9) ◽  
pp. 2185-2198 ◽  
Author(s):  
Kim A. Sjøberg ◽  
Stephen Rattigan ◽  
Jacob F. Jeppesen ◽  
Anne-Marie Lundsgaard ◽  
Jens J. Holst ◽  
...  
Author(s):  
Asma Alshenqiti ◽  
Ghaida Almohammadi

Background: Polycystic ovary syndrome (PCOS) is a common endocrine disorder that affects premenopausal women. It is a multifactorial disease that involves hyperandrogenism, ovulatory dysfunction, insulin resistance and genetic factors. Women with PCOS present with menstrual disorder, hirsutism, and obesity. Diagnosis of PCOS involves evidence of ovulation dysfunction, hyperandrogenism, either physical or biochemical, and ultrasonographic evaluation of the ovarian morphology. There is no single treatment for PCOS but rather it is a symptom-oriented management. Glucagon-like-peptide-1 receptor agonists (GLP-1 RAs) are insulin sensitizers usually involved in the management of PCOS. Aim: This article aims to review the evidence regarding the role GLP-1 RAs in the management of polycystic ovary syndrome. Conclusion: GLP-1 RAs found to improve PCOS outcomes in the form of increasing menstrual frequency, reducing androgens levels, higher pregnancy rates, weight reduction, and improving insulin resistance. Mild and transient adverse events were observed such as nausea, diarrhea, headache, insomnia and mild hypoglycemic events. However, long term studies are required to assess long term effect of GLP-1 RAs and its safety during pregnancy.


2013 ◽  
Vol 304 (7) ◽  
pp. E677-E685 ◽  
Author(s):  
Melissa A. Burmeister ◽  
Jennifer Ayala ◽  
Daniel J. Drucker ◽  
Julio E. Ayala

Glucagon-like peptide-1 (GLP-1) suppresses food intake via activation of a central (i.e., brain) GLP-1 receptor (GLP-1R). Central AMP-activated protein kinase (AMPK) is a nutrient-sensitive regulator of food intake that is inhibited by anorectic signals. The anorectic effect elicited by hindbrain GLP-1R activation is attenuated by the AMPK stimulator AICAR. This suggests that central GLP-1R activation suppresses food intake via inhibition of central AMPK. The present studies examined the mechanism(s) by which central GLP-1R activation inhibits AMPK. Supporting previous findings, AICAR attenuated the anorectic effect elicited by intracerebroventricular (icv) administration of the GLP-1R agonist exendin-4 (Ex-4). We demonstrate that Ex-4 stimulates glycolysis and suppresses AMPK phosphorylation in a glucose-dependent manner in hypothalamic GT1-7 cells. This suggests that inhibition of AMPK and food intake by Ex-4 requires central glucose metabolism. Supporting this, the glycolytic inhibitor 2-deoxyglucose (2-DG) attenuated the anorectic effect of Ex-4. However, icv glucose did not enhance the suppression of food intake by Ex-4. AICAR had no effect on Ex-4-mediated reduction in locomotor activity. We also tested whether other carbohydrates affect the anorectic response to Ex-4. Intracerebroventricular pretreatment with the sucrose metabolite fructose, an AMPK activator, attenuated the anorectic effect of Ex-4. This potentially explains the increased food intake observed in sucrose-fed mice. In summary, we propose a model whereby activation of the central GLP-1R reduces food intake via glucose metabolism-dependent inhibition of central AMPK. We also suggest that fructose stimulates food intake by impairing central GLP-1R action. This has significant implications given the correlation between sugar consumption and obesity.


Author(s):  
Ying Zhao ◽  
Yan Shu ◽  
Ning Zhao ◽  
Zili Zhou ◽  
Xiong Jia ◽  
...  

Long-term sleep deprivation (SD) is a bad lifestyle habit, especially among specific occupational practitioners, characterized by circadian rhythm misalignment and abnormal sleep/wake cycles. SD is closely associated with an increased risk of metabolic disturbance, particularly obesity and insulin resistance. The incretin hormone, glucagon-like peptide-1 (GLP-1), is a critical insulin release determinant secreted by the intestinal L-cell upon food intake. Besides, the gut microbiota participates in metabolic homeostasis and regulates GLP-1 release in a circadian rhythm manner. As a commonly recognized intestinal probiotic, Bifidobacterium has various clinical indications regarding its curative effect. However, few studies have investigated the effect of Bifidobacterium supplementation on sleep disorders. In the present study, we explored the impact of long-term SD on the endocrine metabolism of rhesus monkeys and determined the effect of Bifidobacterium supplementation on the SD-induced metabolic status. Lipids concentrations, body weight, fast blood glucose, and insulin levels increased after SD. Furthermore, after two months of long-term SD, the intravenous glucose tolerance test (iVGTT) showed that the glucose metabolism was impaired and the insulin sensitivity decreased. Moreover, one month of Bifidobacterium oral administration significantly reduced blood glucose and attenuated insulin resistance in rhesus macaques. Overall, our results suggested that Bifidobacterium might be used to alleviate SD-induced aberrant glucose metabolism and improve insulin resistance. Also, it might help in better understanding the mechanisms governing the beneficial effects of Bifidobacterium.


2017 ◽  
Vol 131 (24) ◽  
pp. 2901-2910 ◽  
Author(s):  
Eleni Rebelos ◽  
Brenno Astiarraga ◽  
Roberto Bizzotto ◽  
Andrea Mari ◽  
Maria Laura Manca ◽  
...  

Previous work has shown that potentiation of insulin release is impaired in non-diabetic insulin resistance; we tested the hypothesis that this defect may be related to altered glucagon-like peptide-1 (GLP-1) release. On consecutive days, 82 non-diabetic individuals, classified as insulin sensitive (IS, n=41) or insulin resistant (IR, n=41) by the euglycaemic clamp, were given two sequential mixed meals with standard (75 g, LCD) or double (150 g, HCD) carbohydrate content. Plasma glucose, insulin, C-peptide, non-esterified fatty acids (NEFA) and GLP-1 concentrations were measured; β-cell function (glucose sensitivity and potentiation) was resolved by mathematical modelling. Fasting GLP-1 levels were higher in IR than IS (by 15%, P=0.006), and reciprocally related to insulin sensitivity after adjustment for sex, age, fat mass, fasting glucose or insulin concentrations. Mean postprandial GLP-1 responses were tightly correlated with fasting GLP-1, were higher for the second than the first meal, and higher in IR than IS subjects but only with LCD. In contrast, incremental GLP-1 responses were higher during (i) the second than the first meal, (ii) on HCD than LCD, and (iii) significantly smaller in IR than IS independently of meal and load. Potentiation of insulin release was markedly reduced in IR vs IS across meal and carbohydrate loading. In the whole dataset, incremental GLP-1 was directly related to potentiation, and both were inversely related to mean NEFA concentrations. We conclude that (a) raised GLP-1 tone may be inherently linked with a reduced GLP-1 response and (b) defective post-meal GLP-1 response may be one mechanism for impaired potentiation of insulin release in insulin resistance.


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